Seasonal diet of vicuñas in the Los Andes protected area (Salta, Argentina): Are they optimal foragers?

Torres, Marı́a E.; Puig, Silvia

doi:10.1016/j.jaridenv.2009.10.002

Cited by 20 publications

(24 citation statements)

References 41 publications

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“…We conclude from consistently higher vigilance and flight distances during the dry season that vicuñas were in a more alert situation when forage was more limited, in this case in a similar way to what has been concluded elsewhere (Arzamendia et al. , Mosca Torres and Puig ). In areas or during seasons when vegetative productivity is low and likely constraining populations of herbivores, competition is more likely to occur (Himalayan cold desert, Bagchi et al.…”

Section: Discussionsupporting

confidence: 87%

“…Vicuñas are less selective when habitat quality deteriorates (Arzamendia et al. ), and a switch to a more generalist diet during the dry season is a documented effect elsewhere (Mosca Torres and Puig ) that could explain the variation from OFT predictions in the CFPR. The fact that vicuñas themselves are apparently not at carrying capacity in the CFPR lends credence to different outcomes; for example, in northern Chile, where vicuñas exist at carrying capacity, rainfall is a better predictor of vicuña density and behavior than forage abundance or livestock density, and overall habitat productivity overrides the competitive effects of sympatric livestock (Shaw et al.…”

Section: Discussionmentioning

confidence: 99%

“…Vicuñas are catholic in their diet and consume most plant species occurring in the study area (Borgnia et al. , Mosca Torres and Puig ); we excluded a few plant species that are never consumed by vicuñas. We compared selection by vicuñas of the forage plants we encountered using Ivlev's selection index, or the number of bites relative to the total frequency of each plant species (Ivlev ).…”

Section: Methodsmentioning

confidence: 99%

“…Predictions about the context dependence of the effect of livestock followed two hypotheses. First, behaviors in vicuñas have been shown to conform to predictions in optimal foraging theory (OFT, Mosca Torres and Puig , ). An OFT‐based hypothesis for the CFPR is that time modulates vicuña behavior, so that higher encounter rates of forage plants (more live leaves) or accessibility of forage (fewer dead leaves) during the wet season and in wetlands should lead to more of the vicuña activity budget spent vigilant (and less time spent foraging) during the wet season relative to the dry season, and in wetlands relative to uplands (Cappa et al.…”

Section: Introductionmentioning

confidence: 98%

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Livestock and the functional habitat of vicuñas in Ecuador: a new puzzle

2018

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Abstract. Whether interactions between wildlife and livestock are competitive or facilitative is context dependent. Intermediary factors that explain how context (seasonal or regional characteristics of the ecological community) affects these interactions are rarely reported. We compared activity time and density in vicuñas (Vicugna vicugna) introduced into the Chimborazo Faunal Production Reserve (CFPR), Ecuador, to describe how they interact with livestock. We compared vicuña density in wetlands and uplands (two landscape structures) with and without livestock (two conditions) using an isodar approach. We measured, over two seasons, vicuña forage abundance, composition, preference and accessibility, time vicuñas spent vigilant, and their flight distances on approach. We tested optimal foraging theory relating to the hypothesis that time mediates behavior, and found that vicuñas were no less frequently vigilant, nor were flight distances greater, during a wet season or in habitats of greater forage abundance and accessibility. We also found no evidence that vicuña behavior was density dependent; instead, we found that more time was spent vigilant by vicuñas when they foraged near livestock in rainy regions during the dry season. Although forage abundance was similar throughout CFPR during a dry season, better forage quality in areas occupied by livestock may constitute an effect of their facilitating vicuñas. A puzzling finding, because it was not explained by any of the other variables we measured, was that at low densities vicuñas selected habitat irrespective of livestock, and where their density was higher, it was doubly so adjacent to livestock. We conclude that in the CFPR, spatial heterogeneity in habitat quality determines the interactions between livestock and vicuñas. To support recommendations that minimize competition between wildlife and livestock, and to expand on descriptions of the contexts that determine the direction of species interactions, future study may require a wider sampling of the densities of sympatric large herbivores in general, and, in the CFPR, a closer resolution of spatial heterogeneity in forage plant quality.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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Livestock and the functional habitat of vicuñas in Ecuador: a new puzzle

2018

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“…; Borgnia et al . ; Mosca Torres & Puig ). Currently there is a relatively narrow portion of the Altiplano and Puna where guanacos and vicuñas are both found, but where they segregate spatially in different habitats.…”

Section: Discussionmentioning

confidence: 98%

The influence of the aridAndean high plateau on the phylogeography and population genetics of guanaco (Lama guanicoe) inSouthAmerica

et al. 2012

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A comprehensive study of the phylogeography and population genetics of the largest wild artiodactyl in the arid and cold-temperate South American environments, the guanaco (Lama guanicoe) was conducted. Patterns of molecular genetic structure were described using 514 bp of mtDNA sequence and 14 biparentally-inherited microsatellite markers from 314 samples. These individuals originated from 17 localities throughout the current distribution across Peru, Bolivia, Argentina and Chile. This confirmed well-defined genetic differentiation and subspecies designation of populations geographically separated to the northwest (L. g. cacsilensis) and southeast (L. g. guanicoe) of the central Andes plateau. However, these populations are not completely isolated, as shown by admixture prevalent throughout a limited contact zone, and a strong signal of expansion from north to south in the beginning of the Holocene. Microsatellite analyses differentiated 3 northwestern and 4-5 southeastern populations, suggesting patterns of genetic contact among these populations. Possible genetic refuges were identified, as were source-sink patterns of gene flow at historical and recent time scales. Conservation and management of guanaco should be implemented with an understanding of these local population dynamics while also considering the preservation of broader adaptive variation and evolutionary processes.

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